Energy and the Global Environment for the Physicist as Researcher and Teacher Robert Socolow Princeton University Department of Physics Rutgers University October 11, 2006

Good Advice Long Ago Received Never underestimate a person’s intelligence, nor overestimate what they know.

Outline of Talk 1.The Earth system 2.The energy system 3.Anthropogenic carbon

1.THE EARTH SYSTEM All of this belongs in physics courses

Model 1:  /4 =  T 4.  = 1368 W/m 2  T= 279K Model 2: (1-a)  /4 =  T 4. a = 0.31  T= 254K. (Adding an albedo is better science but gives a worse result.) Actual T e = 288K. Missing: An atmosphere with a greenhouse effect (responsible for 34K of warming). Earth’s Energy Balance Rubin, p. 476

Emissive Power of Sun and Earth (from blackbody equation)

H2OH2O CO 2 CH 4 O 2, O 3 N2ON2O Total ~400 nm ~700 nm Visible Range Rubin, p. 482 Spectrum of the Sun’s Incoming Radiation

Spectrum of the Earth’s Outgoing Radiation Rubin, p. 482

Antarctic Ice Core Source: Gabrielle Walker, “Frozen time,” Nature; Jun 10, 2004; 429, 6992; Research Library Core, pg. 596

CO 2,CH 4 and estimated global temperature (Antarctic ΔT/2 in ice core era) 0 = mean. Source: Hansen, Clim. Change, 68, 269, Temperature, CO 2, and methane track each other

Source: Oak Ridge National Laboratory, Carbon Dioxide Information Analysis Center Mauna Loa CO 2 data,

Today’s atmosphere as a bathtub 780 billion tons of carbon (GtC), as CO CO 2 molecules out of every million air molecules of all kinds 8 GtC/yr removed from below ground and burned 2 GtC/yr added to biosphere, in spite of deforestation 2 GtC/yr absorbed by oceans

Atmospheric CO 2 Concentration with and without sinks “Sinks” Good enough model: Half stays in. Fact about our Atmosphere: 2.1 GtC = 1 ppm

Growth Rate of Carbon Reservoirs

2. ENERGY

Ratio: Solar Input/ Human Use Solar Input: 120x10 15 W [0.69 x 1368 W/m 2 ] x [  x (6370 km) 2 ] Human Use: 13x10 12 W (2 kW/capita) 400 EJ/year Ratio = 10,000. How could we possibly get into trouble? Answer: via carbon dioxide.

Energy fluxes from human activity LocationPopu- lation Primary energy (EJ/yr) Area (m 2 )Flux (W/m 2 ) Fraction of 250 W/m 2 solar flux World’s surface 6* * U.S. (48) 3* * New Jersey 9* # 2.0* # Assumes NJ and US per capita primary energy consumption are the same.

ENERGY UNITS Work UnitHeat Unit SI (“science”) k = 10 3, M = 10 6, G = 10 9 Joule 1 Watt = 1 J/second 1 kWh = 3.6 MJ calorie U.S. (“British”) Foot-poundBtu = 1055J Fuel-derived tce (ton of coal equivalent) = 29.3 GJ toe (ton of oil equivalent) = 41.9 GJ Industry also uses volume units: gallons, liters, barrels, cubic feet, cubic meters. E.g., the scfd, pronounced “scuff,” a standard cubic foot of natural gas per day.

A power plant is a building! 67% of oil used in U.S. goes to vehicles (54% in 1976) 71% of electricity goes to buildings (60% in 1976) Buildings elec is fastest growing element, : Multiple is 2.1 Spaghetti diagram for U.S., 2002 Unit here is the Quad: 1 Quad = Btu.

A larger fraction of electricity goes to buildings in rich countries “Buildings Electricity” = 100% Commercial and Residential + 15% Industrial + 10% Agricultural. Data provided by Paul Waide, graphics by Shoibal Chakravarty All data are for 2002 except U.S point U.S U.S All data are for 2002 except U.S point. Areas of points: proportional to populations.

Second-Law Efficiency Second-Law Efficiency (American Physical Society, 1974) is well known to the chemical engineers as “exergy.” The key concept is the “infinite,” ≈300K heat reservoir at the Earth, from which heat can be withdrawn and to which it can be sent. Heat exchange at temperatures close to 300K can be achieved with very little work. The water heater that converts 90% of its electricity to 50 o C hot water is not an impressive device. It is productive to distinguish energy uses as work and as heat, and also the temperature of the heat required. This leads to emphasis on the co- location of work and heat demands (e.g., cogeneration of heat and power) and high and low temperature heat demands (heat cascades, as in steam integration).

Conventional oil: a negligible fraction of fossil fuel Source for “all fossil fuel”: Bryan Mignone IS92a scenario GtC/yr Today x x x xx xx xx Hubbert oil curve: 3 GtC/yr peak today, 230 GtC (2000x10 9 bbl) total OIL ALL FOSSIL FUEL Hubbert (logistic) curve for all fossil fuel: 5600 GtC total, fit to IS92a x

Global Fossil Carbon Resources Resource Base, GtC Additional, GtC Conventional oil (85 wt. % C)250 Unconventional oil Conventional nat. gas (75% C)240 Unconventional nat. gas Clathrates10600 Coal (70% C) Total Source Rogner, Ann. Rev. Energy and Env. 22, p Also used: 1 toe = 41.9 GJ; 20.3 kg(C)/GJ(oil); 13.5 kg(C)/GJ (gas); 24.1 kg(C)/GJ(coal). 2.1 GtC = 1 ppm. Today’s consumption rate: 7 GtC/yr. OIL DEPLETION WON’T SAVE US FROM THE GREENHOUSE EFFECT.

3. ANTHROPOGENIC CARBON

What if the fossil fuel future is robust, but the Greenhouse problem is severe? Will the fossil fuel system wither away? YESNO Will the case for Greenhouse damage wither away? YESA nuclear or renewables world unmotivated by climate. Most people in the fuel industries and most of the public are here NOEnvironmentalists, nuclear advocates are often here. OUR WORKING ASSUMPTIONS

 2105 Past Emissions Historical emissions Billion of Tons of Carbon Emitted per Year

Billion of Tons of Carbon Emitted per Year Stabilization Triangle Currently projected path Flat path Historical emissions 1.9  2105 Easier CO 2 target ~850 ppm Tougher CO 2 target ~500 ppm The Stabilization Triangle O Interim Goal

(380) (850) The Stabilization Triangle: Beat doubling or accept tripling (details) Values in parentheses are ppm. Note the identity (a fact about the size of the Earth’s atmosphere): 1 ppm = 2.1 GtC  850 ppm  500 ppm Ramp = Delay Flat = Act Now 1.9 (320) (470) (530) (750) (500) (850) Business As Usual GtC/yr Historical emissions Stabilization triangle

The Interim Goal is Within Reach Reasons for optimism that global emissions in 2055 need not exceed today’s emissions: The world today has a terribly inefficient energy system. Carbon emissions have just begun to be priced. Most of the 2055 physical plant is not yet built

Stabilization triangle in CCTP “Potential Scale of CO 2 Emissions Reductions to Stabilize GHG Concentrations: Hypothetical Unconstrained and Constrained Emissions Scenarios,” Fig 3-11, p. 37, Climate Change Technology Program Strategic Plan, US DOE, September

Billion of Tons of Carbon Emitted per Year Currently projected path Flat path Historical emissions 1.9  GtC/y 7 GtC/y Seven “wedges” Wedges O

What is a “Wedge”? A “wedge” is a strategy to reduce carbon emissions that grows in 50 years from zero to 1.0 GtC/yr. The strategy has already been commercialized at scale somewhere. 1 GtC/yr 50 years Total = 25 Gigatons carbon Cumulatively, a wedge redirects the flow of 25 GtC in its first 50 years. This is 2.5 trillion dollars at $100/tC. A “solution” to the CO 2 problem should provide at least one wedge.

Electricity Transportation Heating, other Electricity: 40%; fuels used directly: 60%. Allocation of 6.2 GtC/yr 2000 global CO 2 emissions CO 2 Emissions by Sector and Fuel

15 Ways to Make a Wedge Source; Socolow and Pacala, Scientific American, September 2006, p.54

0 Historical emissions Emissions proportional to economic growth Currently projected path Stabilization Triangle Flat path Virtual Triangle GtC/yr The Virtual Triangle: Large Carbon Savings Are Already in the Baseline Models differ widely in their estimates of contributions to the virtual triangle from structural shifts (toward services), energy efficiency, and carbon-free energy.

Priority #1: Efficient end-use The post-industrialized age features unprecedented private consumption. Life, liberty, and the pursuit of comfort and mobility. The result of this pursuit is that more than 60% of oil is for transport, and more than 60% of electricity is for buildings.

Efficient Use of Fuel Effort needed by 2055 for 1 wedge: 2 billion cars driven 10,000 miles/yr at 60 mpg instead of 30 mpg. 1 billion cars driven, at 30 mpg, 5,000 instead of 10,000 miles/yr. CCTP Strategic Plan (U.S.), Sept. 2006: 1 billion cars driven 10,000 miles/yr at 40 mpg instead of 20 mpg A car at 30 mpg, 10,000 miles/yr, emits 1 tC/yr.

Priority #2: New long-lived stock Today, huge world-wide investment in long-lived capital stock (new infrastructure, new buildings, and new power plants. Making all new capital “carbon smart” is essential, because fixing up later is costly. Energy efficiency and carbon efficiency should be incorporated into all new long-lived capital – in developing and in industrialized countries.

Emission Commitments from Capital Investments Historic emissions, all uses power-plant lifetime CO 2 commitments WEO-2004 Reference Scenario. Lifetime in years: coal 60, gas 40, oil 20. Deter investments in new long-lived high-carbon stock: (e.g., power plants, buildings). Coordinate “green-field” (new) and “brown-field” (replacement). Needed: “Commitment accounting.” Credit for comparison: David Hawkins, NRDC

Wind Electricity Effort needed by 2055 for 1 wedge: One million 2-MW windmills displacing coal power. Today: 50,000 MW (1/40) Prototype of 80 m tall Nordex 2,5 MW wind turbine located in Grevenbroich, Germany (Danish Wind Industry Association)

Electricity Effort needed by 2055 for 1 wedge: 700 GW (twice current capacity) displacing coal power. Nuclear Graphic courtesy of NRC Phase out of nuclear power creates the need for another half wedge.

Power with Carbon Capture and Storage Graphics courtesy of DOE Office of Fossil Energy Effort needed by 2055 for 1 wedge: Carbon capture and storage at 800 GW coal power plants.

Graphics courtesy of DOE Office of Fossil Energy Steam plant by river Gasifier Oxygen plant Coal feeder ramp Gas turbine powered by CO + H 2 IGCC plants are nearly coal CCS plants BP will use petcoke and add, at its Carson refinery, California, USA: 1)CO 2 capture [CO + H 2 O  CO 2 + H 2, CO 2 - H 2 separation, CO 2 absorption ]; 2)H 2 to turbine for power; 3) CO 2 pressurization and export off site for EOR.

Hydrogen Power from Refinery Residues in California Los Angeles Carson refinery (BP) BP will: gasify 4500 t/day of petcoke, producing H 2 and CO 2, at its 260,000 bbl/day Carson refinery burn 800 tons/day of H 2 in turbines for 510 MW of power export off-site 4 MtCO 2 /yr for enhanced oil recovery.

Natural CO 2 fields in southwest U.S. McElmo Dome, Colorado: 0.4Gt(C) in place 800 km pipeline from McElmo Dome to Permian Basin, west Texas, built in the 1980s Two conclusions: 1.CO 2 in the right place is valuable. 2.CO 2 from McElmo was a better bet than CO 2 from any nearby site of fossil fuel burning.

Already, in the middle of the Sahara! At In Salah, Algeria, natural gas purification by CO 2 removal plus CO 2 pressurization for nearby injection Separation at amine contactor towers

The Future Fossil Fuel Power Plant Shown here: After 10 years of operation of a 1000 MW coal plant, 60 Mt (90 Mm 3 ) of CO 2 have been injected, filling a horizontal area of 40 km 2 in each of two formations. Assumptions: 10% porosity 1/3 of pore space accessed 60 m total vertical height for the two formations. Note: Plant is still young.

Coal-based Synfuels with CCS* *Carbon capture and storage Coal-based Synfuels with CCS* *Carbon capture and storage Effort needed for 1 wedge by 2055 Capture and storage of the CO 2 byproduct at plants producing 30 million barrels per day (mbd) of coal- based synfuels. (Global oil: 80 mbd; South Africa synfuels, 0.16 mbd.) Assumption: half of C originally in the coal is available for capture, half goes into synfuels. 120 Mt/yr coal yields 1 mbd synfuels. Consumption (Mt/yr, 2002): World, 4800; China, 1300; U.S and Canada,1100. Liquid-phase synthesis of methanol from CO + H 2. Graphics courtesy of DOE Office of Fossil Energy Result: Coal-based synfuels have no worse CO 2 emissions than petroleum fuels, instead of doubled emissions.

Carbon Storage Effort needed by 2055 for 1 wedge: 3500 MtCO 2 /yr 100 x U.S. CO 2 injection rate for EOR A flow of CO 2 into the Earth equal to the flow of oil out of the Earth today Graphic courtesy of Statoil ASA Graphic courtesy of David Hawkins Sleipner project, offshore Norway

Do wedge strategies get used up? For any strategy, is the second wedge easier or harder to achieve than the first? Are the first 12 million hectares of biofuels more expensive or cheaper than the second 12 million hectares of biofuels ? The first 12 million hectares will be the more favorable sites. But the second 12 million will benefit from the learning (institutional as well as technological) acquired from planting, harvesting, and sellng the first million. The question generalizes to almost all the wedge strategies: Engine efficiency, enhanced oil recovery, wind for hydrogen. All present the same question: Will saturation or learning dominate?

$100/tC Form of EnergyEquivalent to $100/tC Natural gas$1.50/1000 scf Crude oil$12/barrel Coal$65/U.S. ton Gasoline25¢/gallon (ethanol subsidy: 50¢/gallon) Electricity from coal2.2¢/kWh (wind and nuclear subsidies: 1.8 ¢/kWh) Electricity from natural gas1.0¢/kWh Today’s global energy system$700 billion/year (2% of GWP) Carbon emission charges in the neighborhood of $100/tC can enable scale-up of most of the wedges. (PV is an exception.) $100/tC was the approximate EU trading price for a year ending April 2006, when it fell sharply.

$100/tC ≈ 2¢/kWh induces CCS. Three views. CCS Wholesale power w/o CCS: 4 ¢/kWh Transmission and distribution A coal-gasification power plant can capture CO 2 for an added 2¢/kWh ($100/tC). This: triples the price of delivered coal; adds 50% to the busbar price of electricity from coal; adds 20% to the household price of electricity from coal. Coal at the power plant } 6 Retail power w/o CCS: 10 ¢/kWh Plant capital

“60% reduction by 2050” (Blair) + “constant global emissions” leaves a little room for others Under a constant global emissions cap, if emissions from the OECD countries, responsible for almost exactly half of per capita emissions, are reduced by 60% (Blair), emissions from the rest of the world can increase by 60% becomes : OECD 49.9% CO 2 emissions (tC/capita-yr), 10 largest-emitting countries 5.37  2.15/(US pop. growth) 1.13  1.13/(World pop. growth) Source for Graph: Marland et al., 1999, as presented in Rubin, Fig 12.25(b).

Billion of Tons of Carbon Emitted per Year projected path Flat path Historical emissions 1.9  GtC/y 7 GtC/y Seven “wedges” Wedges O Basic Human Needs for cooking and electricity

Earth Engineering How should we perform our new role of Earth engineers? As we learn how the world works as a physical and biological system, we will learn how to manipulate it. We will struggle over goals: levels of risk, intergenerational and intragenerational equity, responsibility for ecosystems and other species. We will struggle over processes: Who decides?

Geoengineering: Parasol in Space Lagrange exterior point, L1: 1.5x10^6 km from Earth Moon is 3.84x10^5 km from Earth Diameter: 2000 km Thickness: 10 μm Mass: 10^11 kg. source: Hoffert, 2002

CCl 3 F CCl 2 F 2 Source: J. Hansen, “The threat to the planet,” July Slides at:

A world transformed by deliberate attention to carbon A world with the same total CO 2 emissions in 2055 as in 2005 will also have: 1.Institutions for carbon management that reliably communicate the price of carbon. 2.If wedges of nuclear power are achieved, strong international enforcement mechanisms to control nuclear proliferation. 3.If wedges of CO2 capture and storage are achieved, widespread permitting of geological storage. 4.If wedges of renewable energy and enhanced storage in forests and soils are achieved, extensive land reclamation and rural development. 5.A planetary consciousness. Not an unhappy prospect!